I. Technical Field
The present invention relates to an apparatus and a method for detecting component attachment which detects the presence or the absence of a component or whether or not a component is attached at a predetermined attachment position in a mounting process of electronic components and the like and particularly to an apparatus and a method for detecting component attachment which detects, at the same time when an attachment operation by pressing is completed, whether or not the component has been attached at the predetermined attachment position.
II. Description of the Related Art
As an apparatus for detecting presence or absence of a component, to detect whether or not a component is sucked at the distal end of a nozzle for sucking and holding a component, an apparatus provided with a movable element capable of coming in/out by reciprocal motion provided in a passage of the nozzle, an annular groove (groove) formed on an outer peripheral face in the middle of the movable element, an optical passage which communicates with the annular groove when the movable element is buried in the nozzle and interrupts the communication with the annular groove when the movable element protrudes from the nozzle, a transmission-type optical sensor provided on the optical passage and the like is known (See Japanese Unexamined Patent Publication No. 2000-133996, for example).
In this apparatus, when the movable element is buried and the annular groove and the optical passage communicate with each other (that is, when detection light emitted from a light-emitting element is received by a light receiving element), the fact that the component is sucked by (remains at) the nozzle is detected, and when the movable element protrudes and the communication between the annular groove and the optical path is shut off (that is, the detection light is shut off), the fact that the component is removed from the nozzle (not remaining therein) is detected by detecting.
However, in this apparatus, since the transmission-type photoelectric sensor (light-emitting element, light-receiving element) needs to be arranged with high accuracy with respect to the nozzle, the structure becomes complicated, assembling accuracy needs to be managed, and costs will rise. Also, there is a fear that, due to slight displacement of the movable element (annular groove), the detection light emitted from the light-emitting element is not received by the light-receiving element and the presence or the absence of the component cannot be detected with high accuracy. Moreover, even if the suction of the component by the nozzle can be detected, whether or not the component is attached at the predetermined position cannot be detected.
Also, as a detecting apparatus for detecting the presence or the absence of a defective press-fit of a component, an apparatus provided with a case having a stepped hole and an optical axis hole crossing the stepped hole, a probe capable of coming in/out the stepped hole and having an annular groove (stepped groove) formed on an outer peripheral face and capable of communicating with the optical axis hole, a light emitter and a light receiver arranged at both ends of the optical axis hole, respectively, and the like (See Japanese Unexamined Patent Publication No. 8-184632, for example) is known.
In this apparatus, when the probe is pressed into a predetermined position in the case, and the annular groove and the optical axis hole communicate with each other (that is, the detection light emitted from the light emitter is received by the light receiver), the fact that the component (contact pin) is correctly press-fitted is detected, and when the probe is not pressed into the predetermined position in the case, and the communication between the annular groove and the optical axis hole is interrupted (that is, the detection light is shut off), the fact that the component (contact pin) is not correctly press-fitted (that is, there is a contact pin of defective press-fit) is detected.
However, in this apparatus, since the transmission-type optical sensor (light emitter, light receiver) needs to be arranged with high accuracy with respect to the case, like the above-mentioned apparatus, the structure becomes complicated, the assembling accuracy needs to be managed, and costs will rise. Also, there is a fear that, due to slight displacement of the probe (annular groove), the detection light emitted from the light emitter is not received by the light receiver, and whether or not the component has been correctly press-fitted cannot be detected with accuracy.
Moreover, as another apparatus for detecting component, an apparatus provided with, in order that a component having a terminal for electric connection is pressed and attached to a printed circuit board, an inspection block for holding a component when it is pressed, an inspection probe contained movably in the inspection block in the press direction and capable of contact with the terminal of the component and the like is known (See Japanese Unexamined Patent Publication No. 5-55795, for example).
In this apparatus, when the terminal of the component is correctly inserted, the inspection probe is brought into contact with the terminal and electrically conducted, and the fact that the terminal has been correctly inserted is detected, while if the terminal of the component is bent and not correctly inserted, the inspection probe is not brought into contact with the terminal and not electrically conducted, and the fact that the terminal is not correctly inserted is detected.
However, in this apparatus, since the presence or the absence of the component (whether or not it is correctly attached) is detected based on whether or not electrical continuity can be obtained, the component to be inspected should be an electrically conductive material, and if the inspection probe (detection block) is attached to a movable portion, a bending frequency of wiring and the like connected to the inspection probe gets high, which leads to a fear of disconnection or the like, and repetition of contact and removal of the inspection probe with and from the terminal of the component causes contact failure and leads to a fear that original detection cannot be carried out surely.